Delaware County, Iowa
The most common soil here is Kenyon, on about 13% of the land: a loam, a balanced mix that crumbles in your hand. Clyde and Fayette come next.
About 45% of the land drains well, and 31% stays wet for long stretches; groundwater comes within two feet of the surface under 31% of it.
USDA rates 97% of the land very limited for a standard septic drain field, and 50% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 7% of the land floods occasionally or more, and bedrock lies within 40 inches under 9% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Delaware County, Iowa, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Poorly drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Delaware County, Iowa. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Clyde-Floyd complex, 1 to 4 percent slopes | 67K | Poorly drained | C/D | Very limited | Very limited |
| Kenyon loam, 2 to 5 percent slopes | 51K | Moderately well drained | C | Somewhat limited | Very limited |
| Dinsdale silt loam, 2 to 5 percent slopes | 8K | Moderately well drained | C | Somewhat limited | Very limited |
| Colo-Ely complex, 0 to 5 percent slopes | 8K | Poorly drained | C/D | Very limited | Very limited |
| Downs silt loam, 5 to 9 percent slopes, moderately eroded | 7K | Well drained | C | Somewhat limited | Very limited |
| Olin sandy loam, 2 to 5 percent slopes | 7K | Well drained | C | Not limited | Very limited |
| Nordness silt loam, 5 to 14 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Bassett loam, 2 to 5 percent slopes | 6K | Moderately well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, 9 to 14 percent slopes, moderately eroded | 6K | Well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, paha, 9 to 14 percent slopes, eroded | 6K | Well drained | C | Somewhat limited | Very limited |
| Marshan clay loam, 0 to 2 percent slopes, rarely flooded | 6K | Poorly drained | C/D | Very limited | Very limited |
| Saude loam, 0 to 2 percent slopes | 6K | Well drained | B | Not limited | Very limited |
| Fayette silt loam, 14 to 18 percent slopes, moderately eroded | 6K | Well drained | C | Very limited | Very limited |
| Dickinson fine sandy loam, 2 to 5 percent slopes | 5K | Well drained | A | Not limited | Very limited |
| Fayette silt loam, paha, 14 to 18 percent slopes, eroded | 5K | Well drained | C | Very limited | Very limited |
| Downs silt loam, 9 to 14 percent slopes, moderately eroded | 5K | Well drained | C | Somewhat limited | Very limited |
| Tama silt loam, driftless, 2 to 6 percent slopes | 5K | Well drained | C | Somewhat limited | Very limited |
| Sawmill silty clay loam, shallow loess, 1 to 4 percent slopes, occasionally flooded | 5K | Poorly drained | C/D | Very limited | Very limited |
| Nordness-Rock outcrop complex, 25 to 60 percent slopes | 5K | Well drained | D | Very limited | Very limited |
| Lawler loam, 0 to 2 percent slopes, rarely flooded | 4K | Somewhat poorly drained | B/D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 50% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 97% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.